On 1/2/2020 12:18 PM, Keith Moore wrote:
On 1/2/20 10:47 AM, Hector Santos wrote:
With hosted end-users, the false positives seen with NATs has been
addressed with the SUBMIT protocol or some other client
authentication that raised the SMTP bar and allowed for receiver
restrictions.
In these days of complete IPv4 address space exhaustion, it can not be
safely assumed that there is no NAT between the MSA and the MX SMTP
server.
Correct.
My approach is how to deal with the exceptions to a well-defined SMTP
protocol element. The good intention exceptions will normally
address the issue promptly, reports are made, including server
whitelisting, client authentication, etc. The bad intention exceptions
don't give a hoot.
So by applying frontend SMTP compliancy-based osmosis filters first,
you will expect to see fast detection and correction of the good
stream, leaving behind the bad stream and less complaints. That is
exactly what has happen, what I have experienced, my customers have
experienced, in the 17 years of applying these SMTP compliancy filters.
Thanks
--
HLS
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